Preheat your Z Grills pellet smoker to medium heat, about 350°F, using your favorite Z Grills wood pellets. Just before cooking the haddock, grease the grill grates by rubbing a small paper towel soaked in olive oil where the fish will touch the grill.
Prepare the haddock by patting it dry with paper towels. Then, oil the fish lightly with some olive oil. You can use a basting brush, a paper towel, or your hands to apply the oil.
Season the haddock filets with salt, pepper, and garlic powder on both sides.
Place 2-3 slices of lemon for each filet on the grill. Then, place the haddock filets on top of the lemons. Leave space between each filet.
Close the grill lid and cook for about 8 minutes. When the internal temperature of the haddock reaches 145°F, remove it from your pellet smoker.
To make the sauce, combine all ingredients in a saucepan and simmer for 5 minutes. You can do this while your haddock cooks, before or after. Once the sauce is done, top the fish with the sauce immediately.
Serve your haddock with brown rice and veggies for a complete meal.